Vertical helical or spiral ore separators have been known for the use of concentrating heavy mineral particles and separating them from lighter rock particles. Typical of such separators are those shown in U.S. Pat. Nos. 629,595, 840,354 and 4,597,861; and in South African Patent Application No. 842,673 filed Nov. 4, 1984. None of these provides a high quality separation due principally to the failure to agitate the slurry and its particles sufficiently to cause good lateral movement across the width of the slurry conduit perpendicular to the direction of travel of the slurry.
It is an object of this invention to provide an improved helical ore separator. It is another object of this invention to provide an improved helical ore separator having a modified flow surface. Still other objects will become apparent from the more detailed description which follows.